When conducting an autopsy, the weight of the unopened corpse is taken before anyone peeks inside. Then the organs are removed and weighed individually. This latter step is important because some disorders affect organ sizes, so if the heart or stomach is unusually heavy, it could help the examiner pinpoint the cause of death.
The first step toward opening the chest is placing a rubber block beneath the torso area, which props up the ribcage. Next, a Y-shaped incision is made; at the bottom of the sternum, a long cut extending down to the pelvis connects with two diagonal cuts that terminate at the shoulders. Rib cutters, bone saws or good old-fashioned pruning shears are then used to remove the rib cage, giving the examiner a clear view of most of the body's major organs. (The brain is extracted in a separate process.)
Regardless, each organ must to be carefully weighed and measured. Though the process might sound tedious, it's sometimes the best way to identify certain maladies. For example, an abnormally heavy heart might indicate that the victim had myocardial hypertrophy. Likewise, kidney sizes fluctuate in cases of chronic progressive nephropathy.
But a medical examiner can't call something abnormal unless he knows what the standards of normalcy are. Tables or charts that document the average weights and dimensions of various organs are consulted during autopsies. As this data is reviewed, the victim's age has to be kept in mind: Babies and adults have differently sized organs, after all.